`Answer:`

`78,` Every garment is inspected by the security men

`79,` Our luggage was weighed at the check-in counter

`80,` New employees are always welcomed by the manager

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$\text{*Structure: Passive voice}$

`@` Câu bị động thì HTĐ:

`+)` $\text{S + am/is/are+VpII + by O...}$

`-)`  $\text{S + am/is/are+ not + VpII + by O...}$

`?)` $\text{Was/Were + (not) + S + VpII + by O...}$

`@` Câu bị động thì QKĐ:

`+)` $\text{S + was/were+VpII + by O...}$

`-)`  $\text{S + was/were+ not + VpII + by O...}$

`?)` $\text{Was/Were + (not) + S + VpII + by O...}$

`#TD`

`78` Every garment is inspected by the security men

`-` "inspect" `->` câu bị động thì htđ

`-` S + V(s/es)

`->` Bđ : S + am/is/are + V-II + ( by O )

`->` "Every garment" - số ít `->` chia "is"

`79` Our luggage was weighed at the check-in counter

`-` "weighed" `->` câu bị động thì qkđ

`-` S + V2/V-ed

`->` Bđ : S + was/were + V-II + ( by O )

`->` "Our luggage" - số ít `->` chia "was"

`80` New employees are always welcomed by the manager

`-` "welcomes" `->` câu bị động thì htđ

`-` S + V(s/es)

`->` Bđ : S + am/is/are + V-II + ( by O )

`->` "New employees" - số nhiều `->` chia "are"

$baoyen.$